91 TII, DP, intake, FCD, catback(still have main cat.).
I was wondering if a fuel pump from an FD with cover me here, and if anyone has done this before, is it an easy install or will there be some rewiring?

 

Bumper!!

 

I think you should have searched on this one man...

... but yes, an FD fuel pump will work great in an FC. FD pumps should be good for appx 330 hp. I ran an FD pump with a full exhaust(dp, mp, catback), intakes, FMIC S-AFC boost .8 kilos - 1.0 kilos.

It installs just like you de-install the FD pump. Looks almost identical.

 

Thanx, I did search, but could'nt find anything on the install.

 

Like jspecracer7 said, it is an easy swap.

With just those mods though, you will run rich, so be prepared to replace your spark plugs every 5k miles or so.

I have a K&N intake, Mindtrain dowpipe, high flow cat, and cat-back, and I still run very rich due to the higher rail pressures with the 3rd gen fuel pump. At least you never have to worry about leaning out the engine with it in there.

 

See my turbo install status #4 for pics and info on installing an FD fuel pump.

 

You dont need to rewire the pump. Its a drop in.

 

I'm assuming that I have to dissconnect battery for this install. And is it safe to say that it is better to run rich then lean out?.

 

What?

Why do you have higher rail pressures with the FD pump? Shouldn't the FPR maintain the same pressures with the FD pump as the FC pump? The only difference is the pressure won't drop at high load because the FD will be able to flow more than the FC pump.

I put in a FD fuel pump in my TII, drop-in, no changes required at all. I measured the voltage at the pump under load with and without the headlights on.

TII pump 11.9 V no headlights 11.6V with headlights on

FD pump 11.6V no headlights, 11.3V with headlights on

Obviously the FD pump draws a little more current, had no problems with the car running rich, tested with a wideband O2 sensor. Rewiring would probably give a little more flow but we didn't need it so I didn't rewire.

Jeff
Triple Threat Motorsports

 

Yes, but it is best to run at stoich (or however you spell it). If I were you I would get an A/F meter and see how you are doing with just your stock fuel pump. Util you are running boost pressures of 10psi or more, you really don't need it.

Running rich will actually cause you to lose power, get crappy milage, chew up spark plugs, and will cause your OEM main cat to overwork and fail (as mine did). There are also arguments that the extra fuel washes down the oil so you get less lubrication where it needs to be.

If you just have to get one, then get a fuel computer (Super AFC etc.) to go with it, to shorten the duty cycle of th primary injectors, and keep it running at stoich.

 

Check your fuel pressure now. Mine jumped almost 10PSI higher than what the stock rating for an 88 T2.

This is typical. The stock pressure regulator can't handle the high flow of the FD (or most other high flow aftermarket fuel pumps). To solve the problem you have to rig up an aftermarket FPR, or get a AFC.

Don't take my word for it, do a search on the topic.

Later

 

I've said it before and I'll say it again: you cannot fine tune with an A/F guage. If you want to do fine tuning, you will need a dyno, wideband O2 sensor, and good voltmeter.

The fuel pressure is raised because the flow from the FD pump is too much for the stock FPR to deal with.

 

Thanks for the back-up Aaron

 

 

Thanx for all the help, I guess I'll get an AFC and boost meter before I install the FD fuel pump, i'm not sure where I'm at after these mods.

 

You don't want to run stoich, except at idle or cruise, where the ecu is running in lean run mode, going back and forth around stoich for gas mileage sake. At WOT, running stoich...14 to 1 ratio, you'd blow up your engine, since the rotary needs to be in the 12 to 1 or 11 to 1 ratio, depending on mods. I think Salgoud was refering to idle and part throttle.

Tim Benton

 

Yes, I was. Sorry for not being more specific.

I have to get out my incorrect habit of thinking of stoich as the the correct mixture at each rpm range, and remember that it actually means 14 to 1 A/F (which WILL blow your engine if you are running that lean at WOT).

All I meant to get across was that with his mods he should still be running at the correct A/F mixture levels with his stock fuel pump even at WOT.

My Bad.

 

Hmmm. Well the a/f ratio was just right, in the 13:1 range with no boost and 11:5:1 under boost up to about 10-10.5 psi where it started to lean out.

So in my experience the stock FPR did just fine with the FD pump.

This WAS NOT a a/f meter, it was a FJO wideband O2 sensor mounted in the DP.

Jeff

 

I have always tuned with an EGT and an A/F meter using the stockl O2 sensor. I have heard the debate left and right about dyno/wide band, but I would NEVER want to run TOO close to the edge on a street car. Especially with all the variables i.e. fuel quality, ambient air temps, etc. I I always tune a hair rich...better 20 hp lost than blown engine's